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A more sustainable material to strengthen concrete structures

For his PhD thesis at the Structural Maintenance and Safety Laboratory (MCS) under the supervision of Emmanuel Denarié, Amir Hajiesmaeili sought to develop the next generation of ultra high-performance fiber-reinforced concrete (UHPFRC). His aim was to develop a material that retains the mechanical properties found in today’s UHPFRC, but without the steel fibers. The UHPFRC that Hajiesmaeili came up with is 10% lighter than UHPFRC with steel fibers, and its environmental impact is 60–70% lower. This new material is so effective that the first tech transfer will take place in 2020, when it will be used to strengthen a bridge. Instead of steel fiber, the researcher used a very stiff synthetic polyethylene fiber that adheres well to the cement matrix. He also replaced half of the cement, a commonly used binder in concrete, with limestone, a material that is widely available around the world.